A cylinder head includes: an exhaust port configured to lead out exhaust gas from combustion chamber; an intake port configured to introduce fresh air into the combustion chamber; an intake air aggregate part configured to aggregate the intake port; and a second EGR pipe in which EGR gas flows, wherein exhaust outlets of the exhaust port and an EGR gas inlet of the second EGR pipe are arranged side-by-side on a flat left side surface, and a fresh air inlet of the intake air aggregate part and an EGR gas outlet of the second EGR pipe are arranged side-by-side on a flat right side surface.

A thermostat is provided at a connection portion between a cooling water supply passage and a bypass passage. When the temperature of the cooling water lies in a low temperature range lower than a first reference temperature, the thermostat allows introduction of the cooling water from the cooling water discharge passage into the cooling water supply passage via the bypass passage and also prevents introduction of the cooling water from the radiator into the engine via the cooling water supply passage. When the temperature of the cooling water lies in a high temperature range equal to or higher than a second reference temperature which is higher than the first reference temperature, the thermostat allows introduction of the cooling water from the radiator into the engine via the cooling water supply passage and also prevents introduction of the cooling water from the cooling water discharge passage into the cooling water supply passage via the bypass passage.

A multi-way coolant valve and a heat pump system having the same include an external housing in which first, second and third external inlets and first, second and third external outlets are formed; and an internal housing provided rotatably inside the external housing to selectively fluidically-connect the first, second and third external inlets, and the first, second and third external outlets, and divided into two stages through which a coolant flows respectively, wherein as the internal housing rotates at a predetermined interval in a selected mode of the vehicle, the first external inlet selectively fluidically-communicates with the first external outlet, the second external outlet, or the third external outlet, the second external inlet selectively fluidically-communicates with the first external outlet or the second external outlet, and the third external inlet selectively fluidically-communicates with the first external outlet, the second external outlet, or the third external outlet.

A coolant pump module for an internal combustion engine is provided. The coolant pump module includes an inlet thermostat and a pump integrated into a single unit. The coolant pump module provides inlet and outlet of coolant to various cooling circuits.

Provided are a cooling system and a method for controlling the same, with which it is possible to bleed air in a coolant flow path, quickly raise a coolant temperature to quickly heat air during air-heating, and quickly lower the coolant temperature to minimize knocking early when knocking occurs. A cooling system 1 comprises a main passage L1 through which a coolant is circulated between an internal combustion engine 2 and a radiator 3, an auxiliary passage 12 through which the coolant is circulated between the internal combustion engine and heat exchangers 4, 5, 6, a thermostat 7 that opens and closes the main passage L1 in response to the coolant temperature, a thermostat bypass path L3 that bypasses the thermostat 7 to allow communication between the internal combustion engine and the radiator, and a motor-operated valve 8 that opens and closes the auxiliary passage and the thermostat bypass path.

An auxiliary coolant pump for circulating a coolant in a vehicle thermal system having a main coolant pump includes a housing, an impeller, a motor selectively driving the impeller, a coolant inlet configured to receive the coolant, a coolant outlet fluidly coupled to the coolant inlet, and a bypass passage fluidly coupled between the coolant inlet and the coolant outlet. When the main coolant pump is on, the auxiliary coolant pump is selectively turned off such that coolant flows through the bypass passage to reduce or eliminate restriction of the coolant flow rate in the thermal system. When the main coolant pump is off, the auxiliary coolant pump is selectively turned on such that coolant continues to flow through at least a portion of the thermal system.

An auxiliary coolant pump for circulating a coolant in a vehicle thermal system having a main coolant pump includes a housing, an impeller, a motor selectively driving the impeller, a coolant inlet configured to receive the coolant, a coolant outlet fluidly coupled to the coolant inlet, and a bypass passage fluidly coupled between the coolant inlet and the coolant outlet. When the main coolant pump is on, the auxiliary coolant pump is selectively turned off such that coolant flows through the bypass passage to reduce or eliminate restriction of the coolant flow rate in the thermal system. When the main coolant pump is off, the auxiliary coolant pump is selectively turned on such that coolant continues to flow through at least a portion of the thermal system.

A switchable mechanical motor vehicle coolant pump includes a rotatable drive shaft, a drive wheel, a coolant pump wheel comprising a radially outer outlet, a control slider, and an actuation system which hydraulically actuates the control slider. The drive wheel and the coolant pump wheel are each connected to the drive shaft. The control slider shifts axially with respect to the coolant pump wheel to at least partially close the radially outer outlet. The actuation system includes pressure chamber(s), an auxiliary pump having an auxiliary pump wheel provided integrally with the coolant pump wheel, and a switchable control valve which controls a pressure level within the pressure chamber(s). The auxiliary pump wheel provides a hydraulic actuation pressure for the pressure chamber(s) and comprises a ring-shaped pumping channel in which pumping vanes are arranged equidistantly along a circumference of the ring-shaped pumping channel so as to define equal pumping chambers therebetween.

A dual-powered railroad vehicle is provided. The vehicle includes a combustion engine having a first cooling circuit; a traction transformer having a second cooling circuit; and at least one radiator for dissipating thermal energy to surrounding air. The first cooling circuit and the second cooling circuit are configured to dissipate thermal energy via the at least one radiator. Further, a method for operating a dual-powered railroad vehicle is provided.

A cooling system for a powertrain includes: a rotating electrical machine unit including a rotating electrical machine; and a power control unit configured to drive the rotating electrical machine. The cooling system includes: a radiator configured to cool a refrigerant; a refrigerant circulation circuit configured to supply the refrigerant flowing out from the radiator to a second cooled portion via a first cooled portion; a bypass flow path bypassing the second cooled portion; a flow control valve configured to adjust the ratio of a second refrigerant flow rate to a first refrigerant flow rate; and a control device configured to control the flow control valve. The control mode of the flow control valve includes a flow rate limiting mode in which the flow control valve is controlled to adjust the ratio such that the second refrigerant flow rate becomes less than the first refrigerant flow rate.